Holographic image containing foil-textile laminate

ABSTRACT

A process for the production of a flexible laminate having an outer and visible layer which provides a holographic effect. A metal foil bearing a holographic image and a layer of plastics size is brought together with a flexible substrate having an outer layer of a plastics material which is comparable with said size. The substrate and foil are brought together with their plastics layers adjacent each other, under conditions of heat and pressure at a level and for a time sufficient to adhere the foil to the substrate but insufficient to destroy the holographic effect.

This is a continuation of application Ser. No. 07/916,843 filed on Apr.8, 1993 now U.S. Pat. No. 5,510,911 and International ApplicationPCT/GB91/00220 filed on Feb. 11, 1991 and which designated the U.S.

This invention relates to a foil laminate and a process for theproduction thereof. In particular, the invention relates to a laminatein which an outer layer provides a holographic effect.

It is known, for example, from British Patent Specification No. 2 205533 A to provide a decorative holographic material having an activatableadhesive surface. The earlier decorative material may be applied tofabric either as such or when the fabric is in the form of an article ofclothing to provide a holographic transfer. The earlier inventionprovides for a water impermeable material between the holographic andadhesive elements so that the transfer is washable. Nevertheless, thetransfer is such that it stiffens the area where it is applied andprovides a rigid item even where the fabric to which it is applied isflexible.

We have now found surprisingly that a flexible laminate in which anouter and visible layer provides a holographic effect can be produced bylaminating together a plastics-coated flexible substrate such as aplastics-coated fabric and a metal foil bearing a holographic patternand a plastics size by bringing together the substrate and foil withtheir plastics layers in contact and applying heat and pressure.

Accordingly, the present invention in one aspect provides a process forthe production of a flexible laminate in which an outer and visiblelayer provides a holographic effect, which process comprises bringingtogether a metal foil bearing a holographic image, and having a layer ofplastics size, and a flexible substrate in which at least an outer layercomprises a plastics material which is compatible with said sizesufficient to enable the plastics material and size to adhere togetherunder conditions of temperature and pressure which do not destroy theholographic effect, the substrate and foil being brought together withtheir plastics layers adjacent each other, and applying to thecombination heat and pressure at a level and for a time sufficient toadhere the foil to the substrate but insufficient to destroy theholographic effect.

In the process of the invention, the metal foil bearing a holographicimage may be any flexible metal foil, but preferably is an aluminiumfoil. Such foils are commercially available as hot stamping foilsbearing a holographic pattern which are produced to provide a foil to beapplied to a rigid substrate, typically a rigid plastics material. Therigid substrate provides a support for the foil so that the holographiceffect may be stabilized. Typically, the size of a commercial foil is apvc (polyvinyl chloride), which is preferred for the foils used in theinvention, but other plastics size layers may be employed in the presentinvention provided they can be adhered to a compatible plastics materialas described above.

Also, the foil used in the process of the invention preferably includesa release layer on that surface of the metal foil which does not carrythe layer of plastics size. That release layer can serve to provideadditional protection for the holographic pattern and is removed aftertreatment in the process of the invention and before the holographiceffect is required. A typical release layer may comprise a polymericmaterial such as Cellophane (registered Trade Mark).

In the process of the invention the flexible substrate may be any suchsubstrate provided only that it is flexible and comprises saidcompatible plastics material. Preferably, however, the substrate is awoven or non-woven web, typically a fabric.

More preferably, the substrate is one which is not only flexible butalso stretchable. Typically, the fabric may be a commercially-availableLycra fabric or any other similar fabric based on a viscose polymer.

Furthermore, the plastics material may be any such material provided itis compatible as defined above. Preferably, however, the plasticsmaterial is a polyurethane and the flexible substrate typically maycomprise 70% viscose and 30% polyurethane by content.

Generally speaking, the flexible substrate is one which has an uncoatedsurface on its reverse side to that carrying the said plastics material.Thus, typically the substrate is a fabric having an uncoated innersurface.

In carrying out the process of the invention, the foil and substrate arefed to a laminating station at which heat and pressure can be brought tobear on their combination. The feeding to the laminating station may beon a continuous or batch basis depending on the requirements of theprocess being effected. Thus, typically the foil and substrate may besupplied continuously or intermittently from rollers on which they maybe stored.

The laminating station may comprise any form of apparatus or devicewhich can supply heat and pressure under the above general requirements.Furthermore, the construction and arrangement of the station may bevaried to suit continuous or batch operation. Thus, in one preferredaspect of the invention the laminating station may comprise at least tworollers between which the foil and substrate may be fed to be pressedtogether and heated. Alternatively, in another preferred aspect the foiland substrate may be brought together in a heated press which typicallymay comprise upper and lower heated plates which can be brought togetherunder pressure.

Generally, the process of the invention is effected at a temperaturebelow about 170° C. because at that temperature and abovecommercially-available foil materials tend to lose their holographiccolours. Preferably also, the temperature at which treatment is effectedis at least above about 140° C., e.g. above about 143° C., with apreferred range being about 150° C. to about 160° C., since below 140°C., wrinkling tends to occur, especially when using stretchable fabricas substrate. However, most preferably the temperature is about 150° C.since a colour shift to pastel colours may take place as temperatures inexcess of 150° C. are employed. Accordingly, unless a particular pasteleffect is required the temperature is kept to the lower end of thepreferred range to maximise the brightness of the holographic colours.

As to pressure, it is preferred to use as high a pressure as is possiblewithin the limits of the press or other apparatus employed. Typically, apressure at or above about 200 gm/cm² may be used, for example, apressure of about 200 to about 210 gm/cm² such as a pressure of about208 gm/cm² which may be applied in a 1000 kg press with a plate area of0.4 m×1.2 m.

Generally speaking, in the process of the invention, the heat andpressure are applied for a sufficient time to enable laminate formationto take place. Thus, a variety of dwell times may be employed, althougha dwell time of about 30 seconds is preferred, especially under theconditions mentioned above.

In the process of the invention the foil may be used to provide aholographic pattern or other holographic effect. Thus, for example, asan alternative to an overall pattern, the foil may embody a variety ofholographic images, either single images or a plurality thereof.Typically, the or each image may be a holographic photo-release image,for example, of a pop-star or the like.

In another aspect, the invention also provides a flexible laminate inwhich an outer and visible layer provides a holographic effect, whichlaminate comprises a layer of metal foil bearing a holographic image, alayer of a flexible substrate and an adhesive layer between thesubstrate and the foil which comprises at least one plastics material ora mixture of at least two compatible plastics materials.

The flexible laminate as defined above generally may be produced by theprocess of the invention. Also, the flexible laminate may typically haveone or more of the features defined herein in connection with thatprocess.

Generally speaking, the flexible laminate of the invention or producedby the process of the invention has a variety of uses all of which mayrequire a flexible material to display a holographic effect. Thus, forexample, the flexible laminate may be used in the theatre forbackground, props or clothing, for other clothing such as skinwear orprotective clothing e.g. for cyclists, for marine equipment such assails for windsurfing boards, or toys.

The fabric of the invention is a fully flexible laminate which generallyhas the same or a similar high degree of flexure as the flexiblesubstrate from which it is made. Thus, the laminate should always becapable of a high degree of flexure and a treated fabric, for example,should be capable of behaving as a fabric so that clothing can be madetherefrom essentially as easily as from the original fabric.

The invention will now be described by way of example only withreference to the following specific Example.

EXAMPLE

A 150 gsm Lycra fabric comprising 70% viscose and 30% polyurethane bycontent and which was clean and free from dust and grease was fed to thetop surface of the lower plate of a Hashima HP124AP 1000 kg fullyautomatic flat fusing press having a fusing plate area of 0.40 m×1.2 mpreheated to 150° C. There was then fed over the Lycra fabric analuminium holographic hot stamping foil with a pvc sizing (supplied byApplied Holographics as E39 with pcv 68 sizing), the pvc sizing facingdownwards onto the fabric. The pressure of the fusing press was then setto 1000 kg and the upper plate of the press brought down on thecombination disposed over the lower plate. The upper and lower plateswere held together for 30 seconds at 150° C. and then the pressure wasreleased and the fused laminate removed.

The laminate was allowed to cool and the release layer of the originalfoil was removed. The result was a flexible laminate exhibiting a verypleasing holographic effect and behaving essentially as the originalfabric. The holographic effect was as bright as that of the originalfoil, the foil appeared to be bonded down into the fabric, and theholographic effect was permanent and fast. Thus, it was impossible towash or scrape off the holographic layer even when the fabric wasstretched, although stretching to a high degree would begin to destroythe fabric thereof.

It is of course to be understood that the invention is not limited tothe specific details given above and numerous variations may be madewithin the spirit and scope of the claims which follow.

We claim:
 1. A flexible laminate of continuous length having an outerand visible layer providing a holographic effect, the laminatecomprising:a layer of metal foil bearing a holographic image; a layer offlexible fabric; and an adhesive layer between the fabric and the foil,the adhesive layer including at least one plastics material; thelaminate behaving essentially as the flexible fabric and being capableof flexing as the fabric such that clothing can be made therefrom. 2.The laminate of claim 2 wherein the at least one plastics materialcomprises a mixture of at least two compatible plastics material.
 3. Aflexible laminate according to claim 1 wherein the metal foil bearing aholographic image is an aluminum foil.
 4. A flexible laminate accordingto claim 1 wherein the laminate has exposed surfaces that are free ofactivatable adhesive.
 5. A flexible laminate according to claim 1wherein the foil is a hot stamping foil bearing a holographic pattern.6. A flexible laminate according to claim 1 wherein the foil has a layerof size thereon directed toward the substrate, the size being apolyvinyl chloride.
 7. A flexible laminate according to claim 1 whereinthe substrate is one which is stretchable as well as flexible.
 8. Aflexible laminate according to claim wherein the fabric is a fabricbased on a viscose polymer.
 9. A flexible laminate according to claim 1wherein the plastics material is a polyurethane.
 10. A flexible laminateof continuous length having an outer and visible layer providing aholographic effect, the laminate comprising:a layer of an aluminum foilbearing a holographic image and having a layer of plastics size; and alayer of flexible fabric including a plastics material compatible withthe plastics size; the plastics size and the compatible plasticsmaterial adhering together the foil and fabric; the laminate behavingessentially as the flexible fabric and being capable of flexing as thefabric.
 11. An article of clothing, comprising:a flexible laminateincluding a layer of metal foil bearing a holographic image, layer offlexible fabric, and an adhesive layer between the fabric and the foil,the adhesive layer including at least one plastics material; thelaminate behaving essentially as the flexible fabric and being capableof flexing as a fabric such that clothing can be made therefrom; wherebythe layer of metal foil is impossible to wash or scrape off of thelaminate regardless of how much the layer of fabric is stretched.
 12. Aflexible laminate having an outer and visible layer providing aholographic effect, the laminate comprising:a layer of metal foilbearing a holographic image; a layer of flexible fabric, and an adhesivelayer between the fabric and the foil, the adhesive layer including atleast one plastics material; the laminate having a flexibility which isessentially the same as the flexibility of the layer of fabric; thelaminate being capable of withstanding stretching, washing, and scrapingwithout the holographic layer of metal foil separating from the layer offabric.
 13. The laminate of claim 12 wherein the holographic layer ofmetal foil bonded to the layer of fabric defies destruction duringstretching until the layer of fabric is destroyed by stretching.